Method of and apparatus for sedimentation testing of blood



C. BROOKS Dec. 21, 1937.

METHOD OF AND APPARATUS FOR SEDIMENTATION TESTING OF BLOOD Filed Oct.18, 1955 (ZWQ E l0 FZWO Qul BL-OOD SETTL/NG CURVE I VENTOR. fi l/yakBraaka ATTORNEY.

Patented Dec. 21, 1937 f UNITED "STATES METHOD OF AND APPARATUS FORSEDI- MENTATION TESTING OF BLOOD Clyde Brooks; New Orleans, La,

Application October 18, 1935, Serial No. 45,631

- 4 Claims. (01. 23 -230) My invention relates to the making of medicalprognosis from the rateofsettlement-of red corpuscles' of blood; anditis designed to provide a method and an apparatus by which such settlementor sedimentation can be efliciently effected and measured,even bytechnicians with but little training. The rate of'settling of the redblood corpuscles is a well known clinical phenomena, enabling aphysician to make a prognosis in many diseases as well'as in operativecases, but this method of prognosis hasbeen relatively little used dueto the highprobability of error and the difficulties and complexitiesinvolved in: making such tests heretofore. l

By my inventionr-such tests may be made'ac curately with a minimumquantity of blood, which is tested in a substantially undiluted andnormal condition without'danger of coagulation, without affording anyopportunity for settlement ofthe red corpus'clesin the test samplebefore the beginning of the test, and without the transfer of the testsample from one container ,to another.

My improved blood sedimentation tester comprises a transparent tube,preferably of glass, containing an axial bore extending thefull lengththereof and having a settling section of substan-.' tially uniform smalldiameter which has a coat. ing of an anti-coagulant appliedthereto,immediately before each test A diametral conical valve seat is formed inthe tube transversely to the axial bore for the re' ception of arotatable glass cock or valve which 5 contains a passage movable by' therotation "of the cock, into and outof registration with the tube bore;The settling section'of the tube is preferably graduated'from the bottomthereof, where'its 9 bore opens into'the-valve seatytoward the distalend of the tube, which may be conically ground for the attachment of ahollow needle.- 'The proximal end of the tube, below the valve seat,

is provided with a mouth piece for applying suc- 5 tion or pressure tothe bore when the valve is open and'whichis cut oil from the settlingsection when the valve is closed to cut off the lower portion of a bloodcolumn in theinstrumentso as to leave in the settling section a columnof 50 accurately measured lengthextending from the valve to the mouth ofthe tip.

' In accordancewith my improved methodfth blood is introduced intothe'proximal end of the tube bore, with the 'valve passage inregistration therewithluntil iti 1111s and projects i a solid" columnslightly beyond the anti-coagulant coated settling section The fiOWgOfblood may be caused by inserting the hollow needle into aveiri or arteryand permitting the pressure [of the i 4 blood therein to cause flow ofblood into the 5- instrument, or the distal end of the tube bore may beapplied todrop the blood formed by pricking the finger, orotherconvenient part and the blood drawn into the" instrument by suctionapplied to the mouthpiece at th e proximal end 10 V of the tube. a a

The characteristic features and advantages of my'improvements willfurtherappear from the following description and the accompanyingdrawing'in illustration thereof.

In the drawing, Figi 1 is an exploded eleva tional view of a bloodsedimentation tester or pipette embodying my invention, parts beingshown in section: Fig. 2 is a fragmentarysectional view, on an enlargedscale, of a'portion of 20 the pipette shown in Fig. 1 as preparedfor useby coating the innersurface of the borewith anti coagulant; andFig. 3 isa chart showing the type of data determinable by my invention and theprognosis indicated thereby In the embodiment of my apparatus showninFigs. 1 and 2 of the drawing, the glass pipette tube l contains asubstantially uniform axialbore or lumen'Z extending the full lengththereof and also contains a transverse conoidal ground valve 36 seat 3.A ground glass valve or co c k 4 is rotat; able in the seat 3 and isprovided with a; bore 5' similar to and adapted to register with thebore 2 in one position of the valve. 1 V

The bore section between the valveseat.. ar 1 d distal point of the tubeforms asettling chamber and {the blood content and corpuscularlse'ttlingtherein may be readily measured by means of'a, graduated millimeterscale etched on thejtube' with a datum, such as a 100 millimetermark, 4dplaced exactly at the intersection ofthe settling chamber formed by theupper bore section vwith the valve seat. The zero point of the scale ispreferably at the mouth of the tip of the bore. H A hollow needle 6 maybe fitted on the tapered distal tip I of the tube 1 and a mouth-piece 81may be connected by the flexible tube 9 with 'the proximalend ill of thetube,

- I have found that coagulation of blood, in quantities suitable fortests of 'therate of settling of red corpuscles in accordance with myinvenf tion, can be'prevented by a mere film of anti-f coagulant on theinner surface of the wall of the bore in which the sedimentation iseffected, p

' In carrying out my process in a preferred mau ner and by means of theillustrated apparatus, there should be prepared a suitableanti-coagulant solution, such as a sterile solution of sodium orpotassium or ammonium oxalate, a sodium citrate, or hirudin, which maybe conveniently put up in a sterile condition in a rubber capped vial.

The blood sedimentation pipette is sterilized, a suitable sterilehypodermic needle fitted on the ground glass tip of the pipette, and apiece of rubber tubing with mouth piece fitted on the opposite end ofthe pipette.

After sterilizing the surface of the rubber cap of the vial ofanti-coagulant solution, the needle,

which is attached to the tip of the pipette, is

inserted through the cap into the solution. With the cock open, theoxalate solution is sucked by means of the mouthpiece through the needleand up into the bore of the pipette, filling it completely as far as, ora little beyond the 100 mark. The cock is then. turned to close thelumen of the pipette, and the needle is withdrawn from the vial oroxalate, solution and the filled pipette placed on some sterile surface.a

A rubber band is adjusted around the patients arm and an antisepticrubbed over the skin covering the veins at the inner side of the bend ofthe elbow. I

The cock of the pipette is now opened and the oxalate solution blownout, leaving a thin film covering the inside of the pipette. The needleis quickly inserted into the lumen of the vein and the blood allowed'to.fiow up through the needle into the lumen ofthe pipette, filling itcompletely as far as the 100 markor a little beyond that point. The cockis then closed, thereby cutting oif the crest of the column and theneedle withdrawn from the vein. The tip of the pipette is, then turnedupward to the vertical position, the needle is removed from the groundglass tip and the tip wiped clean. This leaves the pipette completelyand. precisely filled from. the very mouth of the tip (zero mark) to thepoint where the stop-cock cuts the lumen of the pipette (100 mark). Thusa column of fresh blood. is out. oil and held in the pipette, whichcolumn of blood is precisely 100 mm. in length. This measurement isautomatically effected by the closing of the cock and the removal of theneedle.

The pipette is set in a holder with the tip pointing vertically upward,and the settling of red corpuscles observed; the settling being readfrom the scale and the time. from a stop watch. The settling. should benoted, say, every minute in rapidly settling cases, and every fiveminutes in slower ones. The observations should be kept up vfor twohours andthe results. recorded and plotted n the. form of curves oncoordinate paper.

The graphsshown on the chart in Fig. 3 illustrate, by way of example,the three stages of a case of' pneumonia. The lower curve l2 shows rapidsedimentation, during the period of severe illness; the next curve [3shows a moderately rapid rate of. sedimentation during the period ofconvalescence; and the upper curve l4 shows a normal. healthy rate ofsedimentation after recovery.

, By sterilizing the pipette and needle, when used, the whole test maybe conducted under aseptic conditions so that any test may be extended,if desired, for'tWenty-four hours or-longer, to permit complete settlingof the red corpuscles.

By my improvements the blood is allowed to flow directly from the bloodvessel of the patient into the pipette, where it is immediately set upand the observation of sedimentation at once begun. This simplifies theprocedure and avoids any dilution or mixing of the blood and there is nosettling of the blood corpuscles before the actual observations havebeen started.

The operation of the pipette automatically cuts of? the column of bloodprecisely at-the mark and the removal of the hypodermic needle leavesthe upper meniscus of the column exactly at the mouth of the tip of thepipette, so that the column of blood is exactly 100 mm. long. Thismeasurement being automatic is always uniform and precise, even in thehands of inexpert laboratory workers. The results of measurements ofrate of blood sedimentation are so accurate that very slight alterationsin blood sedimentation can be determined with certainty.

There is no possibility of leakage because the stop-cock effectivelycloses the lower end of the graduated portion of the pipette. No air canget into the blood in the lumen of the pipette since the blood fiowsinto the pipette under its own pressure; If the needle does not fit theground glass tip quite nicely, there'may be some blood leaking out butno air will pass into the pipette. No leakage can occur with thepipetteand' no air bubbles can enter the lumen of the pipette and getmixed with the blood. 1

Having described my invention, I claim:

1. A blood sedimentation pipette comprising a transparent tube and astop cock intercepting said tube intermediate the ends thereof, saidtube containing a capillary bore of.- substantially uniformcross-section extending from said stop cock to one end of the tube, saidtube being graduated from said stop cock to said end, said graduationsreading. from the end toward the stopcock, said tube containing a boreextending from the stop cock oppositely to the first bore, a mouthpiececommunicating with the second bore for drawing blood by suction into thecapillary bore in one position of the stop cock, said stop cock beingmovable to cut oil the suction of the capillary bore when thelatter isfilled with blood.

2. A blood sedimentation pipette comprising a transparent tube and astop cock intercepting said tube intermediate the ends thereof, saidtube having a tapered end and containing a capilliary bore ofsubstantially uniform cross section extending from said stop cock tosaid tapered end, said tube having a scale extending along said bore andproviding graduations reading the entire distance from said end towardthestop cock, said tube containing a second bore extending from saidstop cock, a fiexible'tube communicating with the second bore and havinga mouthpiece for drawing blood by suction into the capillary bore in oneposition of the stop cock, said stop cock being movable to cut offsuction from the first named bore when the latter is filled with blood.

3. A blood sedimentation pipette comprising a transparent tube and astop cock intercepting said tube intermediate the ends thereof, saidtube containing a capillary bore of substantially uniform cross-sectionextending from said stop cock to one end of the tube, a hollow needleremovably fitted on the end of said tube and communicating with saidbore, said tube containing a second bore extending from the stop cook, amouthpiece communicating with the second bore for drawingblood bysuction into the needle and capillary bore in one position of the stopcock, said stop cock being movable to cut off the suction from the firstnamed bore when the latter is filled with blood, and said tube having a.scale reading from its distal end toward the stop-cock by which settlingof said corpuscles may be observed over the entire distance from thedistal end to the stop-cock.

4. The method of sedimentation testing of blood which consists informing a capillary film of anti-coagulant, drawing blood from livingtissue directly into the capillary by suction to form a blood column ofuniform cross section, cutting ofi the blood column intermediate itsends, and positioning the major portion of the blood column so that thepoint at which it was cut off is lowermost until the corpuscles havesettled.

CLYDE BROOKS.

